I have purchased a domain name and I don't have plan to launch my website in the next few months. But one thing I am worrying about is that if in the mean time someone else uses my domain name for his/her website? Is it possible to do so? And if yes, how to protect my domain name?
As long as no one have access to your Domain Control Panel in your domain registrar, the domain name should be safe. To be on the safe side, most registrars allow you to lock a domain, which prevents any WHOIS changes for a couple of months.
Once the access is prevented, no one shall be able to use your domain name. Even if someone uses your domain name with a web host, they need access to the Domain Control Panel to change the nameservers of the domain name. Since the access is prevented and all changes locked, you are perfectly on the safe side.